This unit will show how waves are created, travel, and carry energy, to effect action at a distance from the cause.
Author: Morris H Grade Level: HS Course: Physics
Purpose of Unit
Energy carried by waves, either mechanical or electromagnetic, plays an important part in many processes of the physical world.
Wave Energy detected by our senses of hearing and sight provides us with much of our knowledge of the world around us.
This unit examines how waves are produced, travel, and interact with materials.
Prerequisite Knowledge
Students should have learned about Newton's laws of motion, linear motion, possibly two-dimensional motion such as projectile motion.
Differentiation
Some lessons may be skipped, allowing extra time for the others.
Every unit offers additional explanation and analysis, which may be skipped. For the advanced treatment,students should be comfortable with simple algebraic equations, and their corresponding graphs, both of which will be used to describe and analyze harmonic motion and wave motion.
For all of the lessons in this unit, if possible, at least one setup for each lab should be instrumented with e.g. Vernier Labview or Pasco Probeware so that students can see the graphs develop as the experimental system operates.
This instrumented setup could best be used as part of the lecture.
It would also be good as the attention getter for the opening remarks.
It is not needed for every student station, but could be useful for additional support to some students, as needed.
Learning Performances and Standards
This list of science practices , ranging from simple to more complex, provide a resource for designing assessment tasks.
This unit provides tasks up through levels 4 and 5. Additional inquiry tasks could be provided at higher levels.
1. Identify, describe, … - Students identify the type system, open versus closed, for a process and describe that in a closed system no material (atoms and molecules) can enter or leave the system.
2. Measuring - Students measure important physical magnitudes such as volume, weight, density, and temperature using standard or nonstandard units.
3. Representing data and interpreting representations. - Students using tables and graphs to organize and display information both qualitatively and quantitatively.
4. Predicting/Inferring. - Predicting/inferring involves using knowledge of a principle or relationship to make an inference about something that has not been directly observed.
5. Give an example of - Students produce an example
6. Posing questions. - Students identify and ask questions about phenomena that can be answered through scientific investigations.
7. Designing and conducting investigations. - Designing investigation includes: identifying and specifying what variables need to be manipulated, measured (independent and dependent variables) and controlled; constructing hypotheses; specifying the relationship between variables; constructing/developing procedures that allow them to explore their hypotheses; and determining what observations will be made, how often the data will be collected, and what type of observations will be made.
8. Constructing evidence-based explanations. - Students use scientific theories, models and principles along with evidence to build explanations of phenomena; it also entails ruling out alternative hypotheses.
9. Applying Concepts - Using concepts to solve problems and make relationships.
10. Analyzing and interpreting data. - Students make sense of data by answering the questions: “What does the data we collected mean?” “How does this data help me answer my question?” Interpreting and analyzing can include transforming the data and finding patterns in the data.
11. Evaluating/Reflecting/Making an Argument. - Students ask: Do these data support this claim? Are these data reliable? Evaluate measurement: Is the following an example of good or bad measurement?
Unit content aligns with the following Grade Level Expectations:
PS3 (9-11)-10 Students demonstrate an understanding of waves by
10a. investigating examples of wave phenomena (e.g. ripples in water, sound waves, seismic waves).
10b comparing and contrasting electromagnetic waves to mechanical waves
.10c qualifying the relationship between frequency and wavelength of any wave
PS3 (7-8) - LA Explain the effects on wavelength and frequency as electromagnetic waves interact with matter (e.g., light diffraction, blue sky). (Light Unit only)
Outline of the Concepts Addressed in the Unit
Our knowledge of the universe may be arranged in several related categories: Matter, Structure, and Force and Energy.
Matter is the "stuff" that the Universe is made of. We recognize as facts that every bit of matter must always be someplace, and fully occupies that particular place at that time.
Structure describes how various bits of matter may be arranged, by position and velocity, relative to one another, and how those arrangements may change over time.
Forces may maintain certain structures of matter, or cause structures to change over time.
Energy is inherent in any Structure, because Forces between the parts of a structure represent a form of potential energy.
Some Changes in structure may either go to a state of higher potential energy, and thus require additional energy, or go to a state of lower potential energy, and thus produce excess energy.
Structural changes that produce excess energy may in some cases dispose of it by emitting waves,
while changes that require additional energy may in some cases get it by absorbing waves.
Lesson Sequence
Both sound and light are kinds of waves, which transfer energy from place to place, causing action at a distance from the cause. Because of these common characteristics they are often taught one after the other.
Taking note of the commonalities and of the differences can give students a broader base for their learning. The Unit Plan recognizes this, and follows a parallel plan for both topics. Comparisons are made both from sound to light, and from light to sound, although the topics are presented in sequence, not intermixed.
Lesson Format
Because there are a large number of effects that are best understood by experience, but do not require a full period for observation, the Unit proposes a large number of Mini Labs, set up in related groups to be visited by all students.
The labs are designed to be done by small teams of students.
Labs are first shown as Class Openers, then done by the students.
This is followed by a lecture with student interraction, in which the reults of the lab are analyzed and discussed.
Because this Unit covers a number of closely related concepts, the lessons emphasize the notion of finding similarites and differences between them.
Student Scientific Inquiry
While a "traditional" lab exercise is designed to demonstrate a known principal, and perhaps measure some known physical constant, an inquiry exercise is designed to also provide opportunity for students to ask further questions, and attempt to answer them.
This unit follows a "guided inquiry" approach in which useful lines of questioning are provided to help the students get started.
Every lesson offers the instructor one or more of these starting points.
In brief, a traditional excercise is extended by stating the purpose or question in a way that also invites further questions, and providing the time and resources to attempt further experiments that can help answer them.
The following check list suggests one way to do this:
Collect data
Communicate understanding & ideas
Design, conduct, & critique investigations
Represent, analyze, & interpret data
Experimental design
Observe
Predict
Question and hypothesize
Use evidence to draw conclusions
Use tools, & techniques
About the Mathematics
I would like to explain each topic three ways, in parallel
Conceptually,
Algebra and Graphing,
Calculus.
I think it could be a good (and relatively painless) way to build up math skills in students that don't yet have them.
But I have not done that, yet.
Accessability and Accomodation
The lesson plans start with lab exercises, then a lecture with discussion of what was seen in the laboratory exercises, which are intended to be done by small teams. The instructor may want to form teams in which a student with a special need may be teamed with students that can provide needed assistance.
Additional support for learning includes :
Pre-Lab handout for every lab exercise. These include Graphic Organizers, a Glossary of new terms, and a Readiness Test. (The Readiness Test must be correctly completed as a ticket to do the lab.)
Lab worksheets for data collection and analysis, and worked examples.
Analysis in the following lecture is presented in graphical as well as algebraic form.
Mechanical Waves
As the name suggests, mechanical waves must travel through something, a solid, liquid or gas. Although there are several modes of wave motion, they all share the fact that the motion is transferred from one region to the next, essentially by particles bumping into each other, in any medium, and in solids only, also by tugging on each other.
The interactions cover small distances, but happen very frequently and in large numbers, allowing the wave to travel quickly. A common misunderstanding is that the wave transfers material from place to place, but little or no transfer takes place.
This advance organizer tells students what is coming.
( Be sure to remind them that they can bring in musical instruments when they study Waveforms. )
Light travels as waves, much like Sound but with some differences.
The biggest difference was this: Unlike sound, light can travel through a vacuum.
At first, scientists could not figure out what carried the waves, but the answer was something they already knew about. One could say it was more of a realization than a discovery.
A Light Wave travels as a combination of an Electric Field and a Magnetic Field, both of which can travel through a vacuum.
Remember that a changing Electric Field creates a Magnetic Field,
while a changing Magnetic Field creates a changing Electric Field.
A light wave begins with an oscillating electrical charge, which creates the two changing fields. As they change, they carry the wave forward.
Concept Organizers, including a Pre-lab are assigned as homework reading in preparation for the next lesson. These include a Readiness Test. (The Readiness Test must be correctly completed as a ticket to do the lab, with exceptions for special needs students, who will be assisted and supervised.)
Every concept group is introduced by a set of short Mini Labs, set up as stations to be visited by all students. Each of these stations requires the student to interact with the apparatus, to the extent of varying one or more parameters, while noting the effect of their changes.
Students begin each lab by creating a work sheet, on which they always do these things:
draw a labeled diagram of the lab setup.
identify what variable (or variables) may be changed, and what result is to be observed.
lay out a data table
copy posed questions from the board or use a handout
Students must then do the lab, taking data.
They then can answer some questions about their observations.. The questions are both qualitative and quantitative.
They will also be discussed in the following "What we Learned" session, and this should serve the teacher as formative assessments, providing feedback on how well the lesson has been learned, and what points need further explanation.
These reports are kept by each student, and should be used for study guides.
They will eventually be collected and will be graded, and returned, at the end of the unit.
Summative
There will be a summative test following the section on Sound and Hearing, and another following the section on Light and Vision.
Each of these will have a section for Depth of Knowledge 1 through 3:
Dok1, definitions
Dok2 questions show a figure such as a diagram or graph and present a multiple choice or computed value question
Dok3 written respone drawing on multiple topics within the Unit
Some examples of Dok3 questions:
Why do bats use such high frquency sounds? How can humans use them?
Compare hearing in fish, birds, and mammals. What parts of the sensory system are different and why?
(Same question, but different answers, for Vision in the Light portion of the unit)
How does the much shorter wavelength of Light vs Sound influence Vision vs Hearing?
DoK4 questions take too much time for a sit-down test, but may be assigned with enough time to complete them.
Whales are mammals that live in the ocean, like fish. How has their hearing adapted?
How could a coastal city be protected from extreme ocean waves?
Imagine a Light Instrument, which like a musical instrument, is played in performance to entertain people, but produces light rather than sound. What might it do, and how?
How did you make the topic meaningful for students?
As stated above, the energy carried by waves plays an important part in many processes of the physical world,
and when detected by our senses of hearing and sight provides us with much of our knowledge of the world around us.
Everyone is familiar with the results, if not the processes.
Every class begins with one of the familiar examples.
The final class in Sound examines hearing, and how it evolved to make the most effective use of the properties of sound.
Similarly, the final class in Light examines vision, and how it evolved to make the most effective use of the properties of light.
How did you make use of inquiry?
The several examples of Harmonic Motion systems and modes of Wave Propagation all offer points for similarity and difference observations,
and opportunities to see what parameters have influence on them,
which will be called out in the work sheets for each mini lab.
What are the ways in which you assessed student learning?
Formative assessment of the work sheet for every mini lab.
Summative unit assessment showing a graph or diagram and asking a computation, description or explanation based on it.
How did you take account of students' prior experiences and knowledge?
Regarding content, everyone is familiar with sound and light, so there is a good base level to work from. Regarding techniques, students are, or should be, familiar with basic laboratory skills, but can be given help if needed. Likewise for algebraic and graphic skills.
How will you sequence lessons so that they support the understanding of the learning outcomes?
Starting with simplified models, such as concentrated mass and weightless spring, advancing to more realistic systems.
How will you help students make sense of the materials?
Examples in lab and multiple representations in lecture.
Title: Waves are Action at a Distance
This unit will show how waves are created, travel, and carry energy, to effect action at a distance from the cause.
Author: Morris H
Grade Level: HS
Course: Physics
Purpose of Unit
Energy carried by waves, either mechanical or electromagnetic, plays an important part in many processes of the physical world.Wave Energy detected by our senses of hearing and sight provides us with much of our knowledge of the world around us.
This unit examines how waves are produced, travel, and interact with materials.
Prerequisite Knowledge
Students should have learned about Newton's laws of motion, linear motion, possibly two-dimensional motion such as projectile motion.
Differentiation
Some lessons may be skipped, allowing extra time for the others.
Every unit offers additional explanation and analysis, which may be skipped. For the advanced treatment,students should be comfortable with simple algebraic equations, and their corresponding graphs, both of which will be used to describe and analyze harmonic motion and wave motion.
For all of the lessons in this unit, if possible, at least one setup for each lab should be instrumented with e.g. Vernier Labview or Pasco Probeware so that students can see the graphs develop as the experimental system operates.
Learning Performances and Standards
This list of science practices , ranging from simple to more complex, provide a resource for designing assessment tasks.This unit provides tasks up through levels 4 and 5. Additional inquiry tasks could be provided at higher levels.
1. Identify, describe, … - Students identify the type system, open versus closed, for a process and describe that in a closed system no material (atoms and molecules) can enter or leave the system.
2. Measuring - Students measure important physical magnitudes such as volume, weight, density, and temperature using standard or nonstandard units.
3. Representing data and interpreting representations. - Students using tables and graphs to organize and display information both qualitatively and quantitatively.
4. Predicting/Inferring. - Predicting/inferring involves using knowledge of a principle or relationship to make an inference about something that has not been directly observed.
5. Give an example of - Students produce an example
6. Posing questions. - Students identify and ask questions about phenomena that can be answered through scientific investigations.
7. Designing and conducting investigations. - Designing investigation includes: identifying and specifying what variables need to be manipulated, measured (independent and dependent variables) and controlled; constructing hypotheses; specifying the relationship between variables; constructing/developing procedures that allow them to explore their hypotheses; and determining what observations will be made, how often the data will be collected, and what type of observations will be made.
8. Constructing evidence-based explanations. - Students use scientific theories, models and principles along with evidence to build explanations of phenomena; it also entails ruling out alternative hypotheses.
9. Applying Concepts - Using concepts to solve problems and make relationships.
10. Analyzing and interpreting data. - Students make sense of data by answering the questions: “What does the data we collected mean?” “How does this data help me answer my question?” Interpreting and analyzing can include transforming the data and finding patterns in the data.
11. Evaluating/Reflecting/Making an Argument. - Students ask: Do these data support this claim? Are these data reliable? Evaluate measurement: Is the following an example of good or bad measurement?
Unit content aligns with the following Grade Level Expectations:
Outline of the Concepts Addressed in the Unit
Our knowledge of the universe may be arranged in several related categories: Matter, Structure, and Force and Energy.- Matter is the "stuff" that the Universe is made of. We recognize as facts that every bit of matter must always be someplace, and fully occupies that particular place at that time.
- Structure describes how various bits of matter may be arranged, by position and velocity, relative to one another, and how those arrangements may change over time.
- Forces may maintain certain structures of matter, or cause structures to change over time.
- Energy is inherent in any Structure, because Forces between the parts of a structure represent a form of potential energy.
- Some Changes in structure may either go to a state of higher potential energy, and thus require additional energy, or go to a state of lower potential energy, and thus produce excess energy.
- Structural changes that produce excess energy may in some cases dispose of it by emitting waves,
while changes that require additional energy may in some cases get it by absorbing waves.Lesson Sequence
Both sound and light are kinds of waves, which transfer energy from place to place, causing action at a distance from the cause. Because of these common characteristics they are often taught one after the other.
Taking note of the commonalities and of the differences can give students a broader base for their learning. The Unit Plan recognizes this, and follows a parallel plan for both topics. Comparisons are made both from sound to light, and from light to sound, although the topics are presented in sequence, not intermixed.
Lesson Format
Because there are a large number of effects that are best understood by experience, but do not require a full period for observation, the Unit proposes a large number of Mini Labs, set up in related groups to be visited by all students.
The labs are designed to be done by small teams of students.
Labs are first shown as Class Openers, then done by the students.
This is followed by a lecture with student interraction, in which the reults of the lab are analyzed and discussed.
Because this Unit covers a number of closely related concepts, the lessons emphasize the notion of finding similarites and differences between them.
Student Scientific Inquiry
While a "traditional" lab exercise is designed to demonstrate a known principal, and perhaps measure some known physical constant, an inquiry exercise is designed to also provide opportunity for students to ask further questions, and attempt to answer them.
This unit follows a "guided inquiry" approach in which useful lines of questioning are provided to help the students get started.
Every lesson offers the instructor one or more of these starting points.
In brief, a traditional excercise is extended by stating the purpose or question in a way that also invites further questions, and providing the time and resources to attempt further experiments that can help answer them.
The following check list suggests one way to do this:
About the Mathematics
I would like to explain each topic three ways, in parallel
I think it could be a good (and relatively painless) way to build up math skills in students that don't yet have them.
But I have not done that, yet.
Accessability and Accomodation
The lesson plans start with lab exercises, then a lecture with discussion of what was seen in the laboratory exercises, which are intended to be done by small teams. The instructor may want to form teams in which a student with a special need may be teamed with students that can provide needed assistance.
Additional support for learning includes :
Mechanical Waves
As the name suggests, mechanical waves must travel through something, a solid, liquid or gas. Although there are several modes of wave motion, they all share the fact that the motion is transferred from one region to the next, essentially by particles bumping into each other, in any medium, and in solids only, also by tugging on each other.
The interactions cover small distances, but happen very frequently and in large numbers, allowing the wave to travel quickly. A common misunderstanding is that the wave transfers material from place to place, but little or no transfer takes place.
This advance organizer tells students what is coming.
( Be sure to remind them that they can bring in musical instruments when they study Waveforms. )
Sound Advance Handout
Electromagnetic Waves
Light travels as waves, much like Sound but with some differences.
The biggest difference was this: Unlike sound, light can travel through a vacuum.
At first, scientists could not figure out what carried the waves, but the answer was something they already knew about. One could say it was more of a realization than a discovery.
A Light Wave travels as a combination of an Electric Field and a Magnetic Field, both of which can travel through a vacuum.
Remember that a changing Electric Field creates a Magnetic Field,
while a changing Magnetic Field creates a changing Electric Field.
A light wave begins with an oscillating electrical charge, which creates the two changing fields. As they change, they carry the wave forward.
Light Advance Handout
Assessment Plan
.Formative
Concept Organizers, including a Pre-lab are assigned as homework reading in preparation for the next lesson. These include a Readiness Test. (The Readiness Test must be correctly completed as a ticket to do the lab, with exceptions for special needs students, who will be assisted and supervised.)
Every concept group is introduced by a set of short Mini Labs, set up as stations to be visited by all students. Each of these stations requires the student to interact with the apparatus, to the extent of varying one or more parameters, while noting the effect of their changes.
Students begin each lab by creating a work sheet, on which they always do these things:
Students must then do the lab, taking data.
They then can answer some questions about their observations.. The questions are both qualitative and quantitative.
They will also be discussed in the following "What we Learned" session, and this should serve the teacher as formative assessments, providing feedback on how well the lesson has been learned, and what points need further explanation.
These reports are kept by each student, and should be used for study guides.
They will eventually be collected and will be graded, and returned, at the end of the unit.
Summative
There will be a summative test following the section on Sound and Hearing, and another following the section on Light and Vision.
Each of these will have a section for Depth of Knowledge 1 through 3:
Some examples of Dok3 questions:
(Same question, but different answers, for Vision in the Light portion of the unit)
DoK4 questions take too much time for a sit-down test, but may be assigned with enough time to complete them.
Sound Unit Exam
Rationale
- How did you make the topic meaningful for students?
As stated above, the energy carried by waves plays an important part in many processes of the physical world,and when detected by our senses of hearing and sight provides us with much of our knowledge of the world around us.
Everyone is familiar with the results, if not the processes.
Every class begins with one of the familiar examples.
The final class in Sound examines hearing, and how it evolved to make the most effective use of the properties of sound.
Similarly, the final class in Light examines vision, and how it evolved to make the most effective use of the properties of light.
- How did you make use of inquiry?
The several examples of Harmonic Motion systems and modes of Wave Propagation all offer points for similarity and difference observations,and opportunities to see what parameters have influence on them,
which will be called out in the work sheets for each mini lab.
- How did you take account of students' prior experiences and knowledge?
Regarding content, everyone is familiar with sound and light, so there is a good base level to work from. Regarding techniques, students are, or should be, familiar with basic laboratory skills, but can be given help if needed. Likewise for algebraic and graphic skills.- How will you sequence lessons so that they support the understanding of the learning outcomes?
Starting with simplified models, such as concentrated mass and weightless spring, advancing to more realistic systems.- How will you help students make sense of the materials?
Examples in lab and multiple representations in lecture.Resources on the Internet
These are teacher resources
Safety in the Science Classroom
Rhode Island Science Grade Span Expectations K-12
Oregon Department of Education Student Inquiry Examples
Brigham Young University Science Challenge Student Examples
Human Wave Demonstration
Seismic Waves and the Slinky: A Guide for Teachers
MIT SHM Courseware
Discovery of Sound in the Sea
The Physics of Art Bells
The Musical Harmonic Series
Sound Science With Free Software